Electricity meter



Jaiigzzs, 1929.

1" S. Z. DE FERRANT! ELECTRICITY METER Filed May 25, 1927 2 Sheets-Sheet l fw@ im Jan. 29, 1929. 1,700,669

S. Z'. DE FERRANTI ELECTRICITY METER v Filed May 23, 1927 2 Sheets-Sheet 2 Patented Jan. 29, 1929. i UNETE 'il FFC.

snnesfrinn zum DE en :reen fre nenni, Limmen eL i Application lefl May 192'?, Je.

n the lest pre- Wl. erein thY base is formed This invention relates to electricity meters elect ty ineter as set forth i o :2l l C eznhineblA east iron.

and. inore particularly to the resinas and Cevthereeif f t iivhen construe n als-ze in ineans for s til' Q g @editions in which ilen nr; with en sifen e i ering with the iiel i biie ot rast meter, by i cover-ini, are ank subie es s; whole ont chilled lo :el- 'icipated to nevitle glass covers :for the ineH 1 L inse clz'xscrihecl.

ters which or Coni-s (le not atleet the reading 'io #lifter csi'lnation i .vhieh een only le nt tampering with an drilled *with consi le clil'lic ilty. This 'Antiallv hereina'lter ineusure 'while eilertive te a certain extent, is V.ference te `the accoinlany net- Wholly satisfactory owing` to the tact that rair/ings suoli oevers are ensiiy hreakable by deliberate rrin t the accompanying diagram- 15 aet in the guise of an accidentel act. 7e

The object ol the present invention is te ures l. 'i i ere elevational and plan provide improved constructions in which the v 'nity ine'er Constructed in possibility oi? tampering with the internal resentinvention. mechanism oi' the ineter is entirely prevented istrate p rtions of a ith inaehinahle :in-

2e or st leest is r nelerecl extremely remote, e saune time lil egiei ,in et the sinne with the cover in piso-s as with is removed.

, 5 nie1 'forni the cover l (Figof nieter casing,- (which is he removed du fing calibration of non-inegnetic unrnachinable e steel.

Y Anemis access to the internal mechaoi the ineter by dri line; the cover is 25 venting ireclnlent tempering W n eiectricity ineter in which the reinovebl e of the incter is fori-neel et non-magnetic and unclrillable metal.

Th invention also consists in ineens tor i 30 preventing,r raclulent tampering with an eleeprcventetl and inereover the calibration ot the ff tricity meter in which the @over et the meter is neteterl hy the replacement olf is 'formeel et neneinagnetic undrillahle inancover. lino' i. niorliticatien n forni the mese steel, i-ieeor L H he invention also consists in ineens cover'etnoninagnetic imflrillahleeastirmi ot nreventing ifrsrlulent "ainpering with `an eleocons i, zien about Si" per cent east iron, about e0 ric/ity met r including a cover for the meter 9 per Cent insingggencf--te :intl about i per @cnt formed oit non-inegnetie nnilrillable cest iron, Copper. r

c. composition 87 per cent cast iron, 9 it neles be in this casing or ii: per cent manganese and 4: per cent copper. for exemple e portion reo'nires to he screw- U The invention also eons'sts in .ineens ier threaded for the reception of e sereiv 5 a f5 preventing fraudulent tampering with an hole 3 may ne produeefl by punching (or by eletricity ineter es set forth an any of the last Corin during cest-ing) an@L if desired a plug three Qrecetling paragraphs,wherein the covof comparatively solft instaly such ss milf1 .er or other nnniaehinahle portion of the caseel, rivet l in the i-iole. A further hole is 45 ing,` is provided with comparatively soft metal shown at 9T FiOLre 1GO inserts., e. o1? inilcl steel, riveted into holes l le l..se "Gort-ien 2 oi the meter formed at any desired points. eesir gire O ind 3) this inust "ne The invention also consists in means 'for so es to enable the preventing fraclulent tempering with an eleceeuretl readily there se v Leter wherein the bese which is inafeature of the present m5 chinahie es e Whole is hardened locally f is e bese ot nachineble provided with :t hard shield or shields, thus oit Y haileneflL preventing fraudulent access. ce l) cli g casting,

The invention also consists in means for .nerahle at the eesirecl e5 preventing fraudulent tampering with an stroying itsinaehinahility 11o as a whole. In some cases Where appreciable leakage ot the pe finanent magnet tield through the base is possible, e. g. in certain direct current mercury meters, it may be preferred to employ non-magnetic machinable cast iron to constitute the base.

According to another modification trie base portion of the meter casing to which the principal Worline` parts are liXed is made ot nonmagnetic undrillable cast iron alloy such as that described above in connection with the meter cover or a non-magnetic steel stamping` such as ordinary manganese steel maybe used. In the case ot' castings as above:i holes G (Figure el) may be cast in and blocks 7 ot machinable metal riveted into position. ln case of stampings, (such as 2, Figure holes G may be punched in the material and lilocl-kzs 7 ot' machinable metal riveted in Where desired. In all cases the blocks riveted in are machined to have true 'tacos 8 upon which to mount the working parts of the meter.

Instead ot the above-descrihed lmeans ot rendering the case invulnerable at the desired regions alternative means may be employed. This means comprises the provision Within the base of a shield or shields l() (Figures l and 2) of undrillable metal, e. manganese steel` these shields being` so placed and se cured as to preventaccess to Vulnerable parts oi the meter mechanism should the base be drilled with this intention.

It should be understood that the terms undrillable and cimmachinable employed above are comparative terms intended to indicate that such results are attainable only with Very considerable ditliculty,

Having now described my invention what I claim as new and desire to secure by Letters Patent is l. Means for preventing fraudulent tampering With an electricity meter including a removable meter cover termed of non-magnetic and undrillable metal.

2. Means tor preventing; fraudulent tampering with an electricity meter includingy a removable meter cover termed ot non-magnetic undrillable manganese steel.

3. Means `for preventing Jfraudulent tampering with an electricity meter including a casing of which part unmachinable and is provided With inserts et metal Which is sottv in comparison With the unn'iachinable part.

l. Means 'for preventingv fraudulent tamperingwith an electricity meter mechanism contained in a base, which is macliinable as a Whole, said i'neans comprising at least one locally hardened region.

5. Means tor preventing fraudulent tamperingl With an electricity met-er mechanism contained in a base which is machin-able as a Whole, said means comprising at least one shield oit' undrillable metal.

G. Means tor preventing' fraudulent tampering with an electricity meter mechanism contained in a base otl non-magnetic machinable cast iron, said means comprising at least one locally hardened region,

7. Means for preventing fraudulent tampering' With an electricity meter mechanism contained in a base of non-magnetic mac-hinable cast iron9 said means comprising at least one shield ot undrillable metal.

ln testimony whereof I have signed my name to this specification.

' SEBASTIAN 2mm DE FERRANTL 

